The present application is based on and claims priority from Japanese Patent Application 2000-365235 filed Nov. 30, 2000, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a vehicle AC generator to be mounted in a passenger car, a truck, or the like.
2. Description of the Related Art
Recently, an engine compartment of a car has been narrowed in order to reduce running resistance of the car without sacrificing the space of the passenger compartment. On the other hand, rotation speed of engines is lowered to reduce fuel consumption of the engines.
Therefore, the vehicle AC generator is required to be more compact and more powerful.
U.S. Pat. No. 5,998,903 discloses a compact and powerful vehicle AC generator that employs a plurality of rectangular conductor segments that are connected, by means of welding, to provide a three-phase stator winding.
However, in order to provide higher output voltage to meet a specific demand, the number of turns has to be increased. More number of turns necessitates more number of the conductor segments, which necessarily makes connection work of the conductor segments complicated and troublesome.
Therefore, a main object of the invention is to provide a compact and powerful vehicle AC generator that can provide a comparatively high AC voltage, without necessitating complicated connection work.
According to a feature of the invention, a vehicle AC generator includes a stator core, a stator winding, a rectifier unit. The stator winding is comprised of a plurality of phase-windings, a plurality of first connection segments and a plurality of second connection segments. Each phase winding is comprised of a plurality of U-shaped conductor segments, and each conductor segment has a turn portion forming a first coil-end group disposed on an end of the stator core and a pair of inclined portions forming a second coil-end group disposed on the other end of the stator core. Each pair of the phase-windings that generates AC voltages a 180-degree-electric-angle different from each other is connected by one of the first connection segments to form a series-connected phase-winding. The plurality of series-connected phase windings is connected by the second connection segments, and the first and second connection segments are disposed circumferentially spaced apart from each other.
Therefore, connection and wiring of the stator winding is equally distributed along the coil-end group, and conductor members do not overlap each other.
The stator winding may be comprised of 12 phase-windings that are different in phase from each other and six third connection segments for series connecting those of the phase windings other than the series connected phase windings connected by the first connection segments.
Preferably, the third connection segment extends along one of the coil end groups and disposed one of three portions that are circumferentially spaced apart from each other, and at least a portion of the second connection segment extends along one of the coil-end groups.